Optical Coherence Tomography (OCT) systems are used to capture and generate images of patient tissue layers. These systems often include OCT probes that can invasively penetrate tissue to obtain visualization of tissue within a patient. In ophthalmology, OCT probes are used to obtain detailed images of tissue about the eye or even forming a part of the eye, such as the retina.
In use, an optical light beam is directed through the probe at the tissue. A small portion of this light reflects from sub-surface features of the tissue and is collected through the same probe. Most of the light is not reflected but, rather, diffusely scatters at large angles. In conventional imaging, this diffusely scattered light contributes background noise that obscures an image. However, in OCT, a technique called interferometry records the optical path lengths of received photons, and provides data that rejects most of the photons that scatter multiple times before detection. This results in images that are clearer and that extend in the depth of the tissue.
The OCT probes often include a projecting cannula that can invasively penetrate patient tissue. The probe scans tissue by refracting the optical light beam through a lens disposed at an end of the cannula. A scan can include moving an optical fiber back and forth within the cannula to direct the light beam through the lens and at the tissue at different angles. The length and small diameter of the cannula make it difficult to move the fiber back and forth within the cannula. Further, the small amount of available space within the probe limits the types of actuators that can be utilized. Further still, the OCT probes and associated systems must be capable of being manufactured in a cost-effective manner, which includes the ability to make the probe as a disposable, one-time use device in some implementations.